Network drivers (bridge, host, overlay, none) in Docker - Step-by-Step Execution

Process Flow - Network drivers (bridge, host, overlay, none)

Start Docker Container

↓

Choose Network Driver

↓

bridge

↓

Create virtual bridge

↓

Connect container

↓

Container runs with chosen network

Docker starts a container and picks one network driver. Each driver sets up networking differently, affecting how the container connects to other containers and the outside world.

Execution Sample

Docker

docker network create mybridge

docker run --net=mybridge alpine ping -c 1 google.com

Creates a bridge network and runs a container using it to ping google.com.

Process Table

Step	Action	Network Driver	Effect	Output/Result
1	Create network 'mybridge'	bridge	Creates a virtual bridge network	Network 'mybridge' created
2	Run container with --net=mybridge	bridge	Container connected to 'mybridge' bridge	Container starts with isolated network
3	Container pings google.com	bridge	Uses bridge network to access internet	1 packet transmitted, 1 received
4	Run container with --net=host	host	Container shares host network stack	Container uses host IP directly
5	Run container with --net=overlay	overlay	Container connected to multi-host overlay network	Container can communicate across hosts
6	Run container with --net=none	none	Container has no network interfaces	Container cannot access network
7	Exit	-	-	All network modes demonstrated

💡 All network driver types have been demonstrated with their effects.

Status Tracker

Variable	Start	After Step 1	After Step 2	After Step 3	After Step 4	After Step 5	After Step 6	Final
network_mode	none	bridge	bridge	bridge	host	overlay	none	varies per container
container_network_access	none	isolated bridge	isolated bridge	isolated bridge	host network	multi-host overlay	no network	varies

Key Moments - 3 Insights

Why does a container with --net=host have direct access to the host network?

Because the host driver makes the container share the host's network stack directly, as shown in execution_table step 4, so no network isolation occurs.

What happens if you use --net=none for a container?

The container has no network interfaces and cannot communicate over the network, as shown in execution_table step 6.

How does the overlay network enable communication between containers on different hosts?

The overlay driver creates a virtual network that spans multiple Docker hosts, allowing containers to communicate across hosts, as shown in execution_table step 5.

Visual Quiz - 3 Questions

Look at the execution_table, at which step does the container use the host's network stack directly?

A Step 4

B Step 5

C Step 2

D Step 6

💡 Hint

Check the 'Network Driver' and 'Effect' columns in execution_table row for step 4.

According to variable_tracker, what is the network_mode after step 3?

A none

B bridge

C host

D overlay

💡 Hint

Look at the 'network_mode' row under 'After Step 3' in variable_tracker.

If you want a container completely isolated from any network, which driver should you choose?

A overlay

B host

C none

D bridge

💡 Hint

Refer to execution_table step 6 and the 'Effect' column.

Concept Snapshot

Docker network drivers:
- bridge: default, creates virtual bridge for container isolation
- host: container shares host network stack, no isolation
- overlay: spans multiple hosts for container communication
- none: no network, container isolated
Choose driver with --net option when running containers.

Full Transcript

This visual execution shows how Docker network drivers work. When you start a container, you pick a network driver: bridge, host, overlay, or none. Bridge creates a virtual network bridge isolating containers but allowing internet access. Host shares the host's network stack directly, so the container uses the host IP. Overlay creates a network across multiple Docker hosts for multi-host container communication. None disables networking for the container. The execution table traces creating a bridge network, running containers with different drivers, and their network effects. The variable tracker shows how network_mode and container network access change step by step. Key moments clarify why host shares network, none disables it, and overlay enables multi-host communication. The quiz tests understanding of these steps and effects. This helps beginners see how Docker networking works in practice.